Screw-driver and similar tool.



W. S. THOMSON.

lSCREW DRIVER AND SIMILAR TOOL.

APPucATIoN FILED 1111111.24. 1915.

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WILLIAM S. THOMSON, OF PLANTSVILLE, CONNECTICUT, ASSIGNOR TO THEH. D. SMITH COMPANY, OF PLANTSVILLE, CONNECTICUT, A CORPORATION.

SCREW-DRIVER AND SIMILAR TOOL.

mamon.

Specification of Letters Patent.

Patented Feb. 6, 1916.

Application led March 24, 1915. Serial No. 16,747.

, State of Connecticut, have invented certain new and useful Improvements in Screw- .Drivers and Similar Tools, of which the following is a specification.

My invention relates to improvements in screw-drivers for electrical use, and the object of my improvement is lto produce a screw-driverhaving an insulated shank and handle in which the insulation, which is preferably of rubber, is'firmly secured to the core or body portion, as by vulcanizing, and which by reason of the constructive details is safe and reliable for various conditions'of use, as for high voltage line work, or work around the high tension systems of automobiles, will prevent accidental short circuits and dangerous grounds andcontact by the operator, and my invention ieg-.applicable to other forms of tools than screwldrivers.

In the accompanying drawing: Figure 1 is a planvew of my screw-driver.A Fig. 2 is a sectional view on the line --m lof Fig. 1. Fig. 3 is a side elevation of the .core portion, previous to having the insulation applied thereto. Fig. 4 is a-llsimilar view of a modififed form of core iforthe handle. Fig. 5 is a plan view of the same. Fig. 6 is a sectional view of the finished screw-driver. Fig. 7 is a sectional view of another screw-driver, showing a modified form of building up the handle on the handle core shown in Fig. 4.

My improved screw-driver comprises a core consisting of a handle portion 10 at one end and a shank portion 11 extending from one end of the same, which are covered with insulation 12 and a bit portion 13 extending from the insulated shank portion 11 having a screw-driver bit at the extreme end. The core portion 10 is of proper size and shape to give the desired dimensions for the finished handle andis solid, except for holes 14 that are provided as an expedient for properly positioning the core during the process of applying the insulation, and has the outer end rounded and the inner end, adjacent the junction 15 with the shank portion 11, is tapered and generally conical. A

short uninsulated cylindrical shank extens ion 16 connects the insulated shank portion 11 with the bit portion proper 13. The shank portion 11 is cylindrical and appreciably elongated, and is reduced relatively to the adjacent uninsulated shank portion 16 so that a shoulder 17 is formed at the junction therewith.l The portion 18 of the insulation 12 covering the shank portion 11 abuts against the shoulder 17 so that the exterior of the insulation along the shank portion 11 is fiush with that of the said shank extension 16. Accordingly, as described, the outer surface of the screw-driver is cylindrical in form from the bit end for an appreciable distance along the shank extension 16 and the insulation 18 over the shank portion 11, and tapers from the cylindrical form from the shank portion 11, at the junction 15, to the body of the handle.,

The holes 14 are provided on opposite sides to permit the entry of holding devices for properly positioning the core in the mold in the process of applying the insulation. As the holding devices engage with the bottoms 19 of the holes and cover the same, while the insulation is being applied generally or to the other' parts, the said bottoms 19 would be inaccessible to the insulating compound, and when the holding devices are removed the said bottoms would be bare, or uninsulated. j

I provide proper insulation .for the holes 14 in the following manner. It willibe noted that the handle portion 10 of the-- core is" of appreciable thickness, being in fact slightly bulky. I form the holes 14 of appreciable depth,l so that the two bottoms are separated simply by a thin web 20, the bottoms 19 being of proper size to accommodate the holding devices, and the side walls 21'are formed tapering. Then by using holding devices cylindrical in form the insulation 12 will fill in around the same and fill the space between the holding devices and the tapered side walls 21, leaving a cylindrical hole 22 in the place of the holding device.

The hole 22 is filled in with some form of sealing compound 23, such as sealing wax or any of the sealing compounds used for covering the exposed parts and filling the holes in porcelain andslate bases for electrical fixtures.

The insulation 12 is preferably a high grade rubber, vulcanized in place, and extends over the core at a uniform depth.

A lighter handle construction is provided in the modified form of handle shown 1n Fig. 4, the handle portion 0f the core comprising a central web 10?, which in some cases may have enlargements at the ends of the handle portion, comprising a head 24 at the outer end and a bolster 25 at the junction 15 with the shank portion 11. In this case the insulation 12a comprises a solid portion 26 on each side of the web 10a to build up the handle body and which is homogeneous and integral with the outer portion corresponding to the layer 12 used in the style shown in Fig. 1. In this case the holding devices engage with the web 10a and the holes 12 are formed as before, during the insulating process, and these are afterward filled.

A light handle result similar to that obtained by the style shown in Fig. 4 is obtained by the style shown in Fig. 7 in which the solid portions 26" used to build up the body of the handle are made of an inferiorgrade of material, which preferably has some insulating value, even though if appreciably less than that of the high grade outer layer 12b but which is considerably less expensive, such as one of the numerous materials suitable for molding and known as composition.

The handle portion is built up by the composition to a size to correspond to that of the solid metal core used in the style shown in I Fig. 1 and is finally coated with the layer 12" of high grade material.

It will be noted that any of the styles of screw-drivers shown is adapted to be readily inserted in between a group of wires without unduly disturbing them or catching on any of them because of the absence of any shoulders or projections, and on account of the long length of the insulated shank there.

portion, a shank extension, and a bit portion,

a layer of insulating material extending continuously over the said handle portion and shank portion and secured thereto by vulcanizing, the said shank portion being reduced relatively to the said shank extension, and the periphery of the said insulating layer on the shank portion being Hush with the periphery of the said shank extension.

WILLIAM S. THOMSON.

Witnesses:

G. 1t. BOND, E. H. GALPIN. 

